RU2503683C2 - Diarylalkylphosphonates and methods for production thereof - Google Patents

Abstract

FIELD: biotechnology.

SUBSTANCE: invention relates to a method of producing diarylalkylphosphonate from triarylphosphite and trialkylphosphite or alkanol. Triarylphosphite and a catalyst are mixed to form a triarylphosphite catalytic mixture; the triarylphosphite catalytic mixture is heated to reaction temperature from about 210°C to about 260°C; the heated triarylphosphite catalytic mixture is then mixed with (i) trialkylphosphite in molar excess of 0.01% to about 3% with respect to triarylphosphite; and (ii) alkanol in molar excess of 0.01% to about 3% with respect to triarylphosphite; and the triarylphosphite mixture then reacts with the trialkylphosphite or alkanol to form diarylalkylphophonate.

EFFECT: novel efficient method of producing diarylalkylphophonate is disclosed.

20 cl, 11 ex, 3 tbl

Description

Various methods for the synthesis of diaromatic alkylphosphonates are known. Methods for producing diaromatic alkyl phosphonates are described, for example, in US Pat. Nos. 4,152,373 and 4,377,537. In US Pat. No. 4,152,373, diaromatic alkyl phosphonates are prepared by reacting triaromatic phosphite, specifically triphenyl phosphite, and methanol in the presence of a catalytic amount of methyl iodide. The reaction temperature is higher than the boiling point of methanol (~ 65 ° C), and therefore, a slow addition of methanol is required in order to prevent its evaporation from the reactor. In this reaction, phenol is a by-product that is distilled off from the product in a separation step.

US patent No. 4377537 describes a method for the synthesis of diaromatic methylphosphonates by reacting triarylphosphite (specifically triphenylphosphite) and trialkylphosphite (specifically trimethylphosphite) in the presence of a catalytic amount of methyl iodide. The reaction typically involves heating the components to a final temperature of about 230 ° C. for up to 1 hour. The exothermic reactions of this method occur in two temperature regions, the first about 100 ° C and the second about 210 ° C. Due to the exothermic (and even explosive) nature of these reactions, when using a batch process, the reaction scheme described in US patent No. 4377537, limited to small-scale production of diaromatic alkylphosphonates.

Although some diaromatic alkylphosphonates (e.g., diphenylmethylphosphonate, registration number 7526-26-3) are commercially available, they are relatively expensive.

SUMMARY OF THE INVENTION

The embodiments disclosed herein include a process for preparing an optionally substituted diarylalkylphosphonate comprising the steps of: combining at least one optionally substituted triarylphosphite and at least one catalyst to form a triarylphosphite catalyst mixture; heating the triarylphosphite catalyst mixture to a reaction temperature; adding to the heated triarylphosphite catalyst mixture (i) at least one optionally substituted trialkylphosphite in a molar excess of less than about 10% based on the optionally substituted triarylphosphite; or (ii) at least one optionally substituted alkanol in a molar excess of less than about 10% based on the optionally substituted triaryl phosphite; and reacting the triarylphosphite mixture and at least one optionally substituted trialkylphosphite or at least one optionally substituted alkanol to form an optionally substituted diarylalkylphosphonate.

In some embodiments, the optionally substituted trialkyl phosphite may be in a molar excess of 0% to about 3% of the optionally substituted triaryl phosphite, and in other embodiments, the optionally substituted trialkyl phosphite may be in a molar excess of less than about 1% of the optionally substituted triaryl phosphite. In specific embodiments, the triarylphosphite catalyst mixture is stored for an indefinite period of time prior to heating.

Optionally substituted triarylphosphite in various embodiments may have the general formula (III):

where R _1a , R _1b and R _1c , each independently, may have the general formula (II):

where R ₃ , R ₄ , R ₅ , R ₆ and R ₇ each independently, may be selected from hydrogen, trifluoromethyl, nitro, cyano, C ₁ -C ₂₀ alkyl, aromatic radical, halide, C ₁ -C ₂₀ alkyl simple ether, benzyl halide, benzyl ether, aromatic ether and combinations thereof. In some embodiments, the optionally substituted triarylphosphite may be triphenylphosphite.

The optionally substituted trialkylphosphite in various embodiments may have the general formula (IV):

where R _2a, R _2b and R _2c , each independently, may be C ₁ -C ₂₀ alkyl, and in certain embodiments, the optionally substituted trialkyl phosphite may be trimethyl phosphite.

The optionally substituted alkanol in various embodiments may be selected from optionally substituted alkanols of general formula (V):

where R ₈ and R ₉ each independently may be hydrogen or C ₁ -C ₂₀ alkyl, and in certain embodiments, the optionally substituted alkanol may be methanol.

In some embodiments, the optionally substituted trialkylphosphite or optionally substituted alkanol can be added to the heated catalyst mixture by methods including but not limited to: adding optionally substituted trialkylphosphite or optionally substituted alkanol under the surface of the heated triarylphosphite catalyst mixture; adding an optionally substituted trialkylphosphite or an optionally substituted alkanol to the surface of the heated triarylphosphite catalyst mixture; and their combination.

The catalyst in some embodiments may be an alkylation catalyst, and in various embodiments, the catalyst may be an alkyl halide of general formula (VII):

R ₁₀ -X (VII)

where R ₁₀ may represent C ₁ -C ₂₀ alkyl, and X may represent a halide. In specific embodiments, the implementation of the catalyst may be CH ₃ I.

In some embodiments, the catalyst is in excess of less than about 0.15% by weight of the total weight of optionally substituted trialkylphosphite or optionally substituted alkanol and optionally substituted triarylphosphite. In other embodiments, the reaction temperature may be at least higher than the exotherm that occurs when the optionally substituted triarylphosphite is mixed at room temperature with a catalyst and optionally substituted trialkylphosphite and heated, and in specific embodiments, the reaction temperature may be from about 210 ° C. to about 260 ° C. In further embodiments, the method may include the step of maintaining the reaction temperature during the addition of the mixture.

In certain embodiments, the optionally substituted diarylalkylphosphonate obtained may generally not contain an optionally substituted triarylphosphite, and in other embodiments, the resulting optionally substituted diarylalkylphosphonate may be substantially free of an optionally substituted aryl halide. Therefore, in specific embodiments, the method may include the step of using the resulting optionally substituted diarylalkylphosphonate in subsequent reactions without purifying the optionally substituted diarylalkylphosphonate.

Other embodiments of the invention include a method for producing an optionally substituted diarylalkylphosphonate, comprising the steps of: using at least one optionally substituted triarylphosphite; adding to the optionally substituted triarylphosphite at least one catalyst; adding to the optionally substituted triarylphosphite (i) at least one optionally substituted trialkylphosphite in a molar excess of less than about 10% based on the optionally substituted triarylphosphite; or (ii) at least one optionally substituted alkanol in a molar excess of less than about 10% based on the optionally substituted triaryl phosphite; and reacting an optionally substituted triarylphosphite, at least one catalyst, an optionally substituted trialkylphosphite, or an optionally substituted alkanol to form an optionally substituted diarylalkylphosphonate.

In some embodiments, the catalyst may be an alkylation catalyst, and in certain embodiments, the catalyst may be an alkyl halide of general formula (VII):

R ₁₀ -X (VII)

where R ₁₀ may represent C ₁ -C ₂₀ alkyl, and X may represent a halide. In specific embodiments, the catalyst may be CH ₃ I. In further embodiments, the catalyst may be present in excess of less than about 0.15% by weight of the total weight of the mixture and optionally substituted triaryl phosphite.

In other embodiments, the reaction step may include heating to a reaction temperature at least above the exotherm that occurs when the optionally substituted triarylphosphite is mixed at room temperature with a catalyst and optionally substituted trialkylphosphite, and in certain embodiments, the reaction temperature may be from about 210 ° C to approximately 260 ° C. In further embodiments, the method may further include the step of maintaining the reaction temperature during the addition and reaction steps.

In still other embodiments, the invention includes a composition comprising a phosphonium salt prepared by combining an optionally substituted triarylphosphite and at least one catalyst in excess of less than about 0.15% of the optionally substituted triarylphosphite.

In some embodiments, the catalyst for the composition may be an alkylation catalyst, and in specific embodiments, the catalyst may be an alkyl halide of general formula (VII):

R ₁₀ -X (VII)

where R ₁₀ may represent C ₁ -C ₂₀ alkyl, and X may represent a halide. In certain embodiments, the catalyst may be CH ₃ I.

DETAILED DESCRIPTION OF THE INVENTION

Before the presented compositions and methods will be described, it should be understood that they are not limited to the specific compositions, methodologies or protocols described, as they may vary. It should also be understood that the terminology used in the description exists only for the purpose of describing specific versions or embodiments and is not intended to limit their scope, which should be limited only by the appended claims.

It should also be noted that, as used in the description and in the claims, singular nouns also include plural references, unless the context clearly indicates otherwise. Unless otherwise specified, the technical and scientific terms used in the description have the same meanings as are understood by ordinary specialists in this field. Although any methods and materials similar or equivalent to those described herein can be used in practice or in testing the disclosed embodiments, preferred methods, devices, and materials are now described.

“Optional” or “optionally” means that the event or circumstance described below may or may not occur, and that the description includes cases when the event occurred and cases when it did not occur.

“Basically not” means that the event described below can occur for the most part in less than about 10% of cases, or that the component described below can make up for the most part in less than about 10% of the total composition, in some embodiments, but others, for the most part, about less than 5%, and still for the most part, about less than 1%.

The term "alkyl" or "alkyl group" refers to a branched or unbranched hydrocarbon or group with 1-20 carbon atoms, such as, but not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert- butyl, octyl, decyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, etc. "Cycloalkyl" or "cycloalkyl groups" are branched or unbranched hydrocarbons in which all or some of the carbon atoms are arranged in a ring, such as, but not limited to, cyclopentyl, cyclohexyl, methylcyclohexyl, and the like. The term "lower alkyl" includes an alkyl group with 1-10 carbon atoms.

The term “aryl” or “aryl group” refers to monovalent aromatic hydrocarbon radicals or groups consisting of one or more fused rings, of which at least one ring is aromatic in nature. Aryls may include, but are not limited to, phenyl, naphthyl, biphenyl ring systems, and the like. The aryl group may be unsubstituted or substituted by various substituents, including, but not limited to, alkyl, alkenyl, halide, benzyl, alkyl or aromatic ether, nitro, cyano and the like. and their combinations.

"Substituent" refers to a molecular group that replaces hydrogen in a compound and may include, but is not limited to, trifluoromethyl, nitro, cyano, C ₁ -C ₂₀ alkyl, aromatic or aryl group, halide (F, Cl, Br, I) , C ₁ -C ₂₀ alkyl ether, benzyl halide, benzyl ether, aromatic or aryl ether, hydroxy, alkoxy, amino, alkylamino (-NHR '), dialkylamino (-NR'R ") or other groups which do not interfere the formation of diarylalkylphosphonate.

As defined herein, an “arylol” or “arylol group” is an aryl group with a hydroxyl substituent, an OH group, in the aryl ring. Non-limiting examples of arylols are phenol, naphthol, and the like. A wide variety of arylols can be used in embodiments of the invention and are commercially available.

The term "alkanol" or "alkanol group" refers to a compound comprising alkyl with 1-20 carbon atoms or more, having at least one hydroxyl group as a substituent. Examples of alkanols include, but are not limited to, methanol, ethanol, 1- and 2-propanol, 1,1-dimethylethanol, hexanol, octanol, and the like. Alkanolic groups may optionally be substituted with the substituents described above.

The term "alkenol" or "alkenol group" refers to a compound comprising an alkene with 2 to 20 carbon atoms or more, having at least one hydroxyl group as a substituent. Hydroxyl can be located in one of the isomeric configurations (cis or trans). Alkenols may be further substituted with one or more substituents described above, and may be used instead of alkanols in some embodiments of the invention. Alkenols are known to those skilled in the art and many are readily available commercially.

Embodiments of the disclosure include methods for preparing optionally substituted diarylalkylphosphonates, optionally substituted diarylalkylphosphonates obtained using such methods, and compositions related to these methods. The method in various embodiments may include combining an optionally substituted triaryl phosphite with at least less than 10% molar excess or an optionally substituted trialkyl phosphite or optionally substituted alkanol, and with a catalytically effective amount of catalyst. In embodiments, the optionally substituted triarylphosphite may be heated to a predetermined reaction temperature before adding the optionally substituted trialkylphosphite or optionally substituted alkanol and a catalytically effective amount of catalyst, and this reaction mixture may be reacted to form an optionally substituted diarylalkylphosphonate. Without being bound by any theory, combining the components at room temperature and heating to a suitable reaction temperature can induce an uncontrolled exothermic reaction, potentially creating a strong exothermic effect.

In certain embodiments, an optionally substituted diarylalkylphosphonate can be formed immediately after the addition of an optionally substituted trialkylphosphite or an optionally substituted alkanol and a catalytically effective amount of catalyst to a heated optionally substituted triarylphosphite. In other embodiments, the heat generated by the reaction can be controlled by the rate at which the optionally substituted trialkylphosphite or optionally substituted alkanol and a catalytically effective amount of catalyst are added to the heated optionally substituted triarylphosphite. Therefore, an optionally substituted trialkylphosphite or an optionally substituted alkanol and a catalytically effective amount of catalyst can be added using a controlled method, for example, dropping over or pumping below the surface of the reaction mixture.

In other embodiments, an optionally substituted triarylphosphite and a catalytically effective amount of a catalyst, such as, but not limited to, methyl halide, can be combined to form a stable triarylphosphite catalyst mixture. The triarylphosphite catalyst mixture can be stored after being prepared at ambient temperature for an indefinite period of time, and / or the triarylphosphite catalyst mixture can be heated to a predetermined reaction temperature, and the production of an optionally substituted diarylalkylphosphonate can be initiated by the addition of at least less than 10% molar an excess of optionally substituted trialkylphosphite or optionally substituted alkanol to the heated triarylphosphite catalyst mixture. The triarylphosphite catalyst mixture in embodiments may further comprise an excess of optionally substituted triarylphosphite with respect to the catalyst.

Without being bound by any theory, when combined with a catalyst, an optionally substituted triarylphosphite can react with the catalyst to form a triarylphosphite catalyst mixture, so that an uncontrolled exothermic reaction is generally not observed. In some embodiments, the rate of addition of the trialkyl phosphite to the heated reaction mixture can be set so as to further control the exothermic effect. Moreover, the triarylphosphite catalyst mixture can significantly increase the boiling point of the catalyst, so that the triarylphosphite catalyst mixture can be heated to a temperature above 40 ° C mainly without loss of catalytic activity. Therefore, the production of optionally substituted diarylalkylphosphonate can occur at high temperature mainly without loss of catalyst due to evaporation of the catalyst, which can occur when the catalyst is added with optionally substituted trialkylphosphite or optionally substituted alkanol, or added separately, either by dropping into the reaction mixture or by pumping below the surface of the reaction mixture.

In certain embodiments, the optionally substituted diarylalkylphosphonate can be formed immediately after the addition of the optionally substituted trialkylphosphite or optionally substituted alkanol to the heated triarylphosphite catalyst mixture. In other embodiments, the heat generated by the reaction can be controlled by the rate at which the optionally substituted trialkylphosphite or optionally substituted alkanol is added to the heated triarylphosphite catalyst mixture. Therefore, optionally substituted trialkylphosphite or optionally substituted alkanol can be added using a controlled method, for example, dropping on top or pumping below the surface of the reaction mixture.

In embodiments of the invention, the predetermined reaction temperature may be at least higher than the highest exotherm when the components are mixed at ambient temperature and heated to allow the reaction to occur, and in certain embodiments, the reaction temperature may be at least higher than the highest exotherm and lower than the temperature, wherein the optionally substituted diarylalkylphosphonate obtained is thermally decomposed. The reaction temperature in the embodiments may therefore be from about 210 ° C. to about 260 ° C., and in other embodiments, the reaction temperature may be from about 230 ° C. to about 260 ° C. Without being bound by any theory, the large observed uncontrolled exothermic effect, when the reactants are mixed at room temperature and heated, can be eliminated by carrying out the reaction at a temperature that is at least higher than the highest exotherm, and the volatility of the reaction mixture can be reduced, allowing the reaction leak more safely.

The optionally substituted diarylalkylphosphonates obtained by any of the methods described above may generally be free of impurities, such as, for example, residual optionally substituted triarylphosphite, which may allow the optionally substituted diarylalkylphosphonate obtained by the methods of embodiments of the present invention to be used in subsequent condensation reactions mostly without the formation of toxic by-products.

Diarylalkylphosphonates or optionally substituted diarylalkylphosphonates of embodiments may have the general formula (I):

where R ₂ may be C ₁ -C ₂₀ alkyl and R ₁ may be an aromatic or aryl group, or a substituted aryl group of the formula (II):

where R ₃ , R ₄ , R ₅ , R ₆ and R ₇ may independently represent any substituent, including, but not limited to, hydrogen, C ₁ -C ₂₀ alkyl, aromatic or aryl group, trifluoromethyl, nitro, cyano, halide ( F, Cl, Br, I), C ₁ -C ₂₀ alkyl ether, benzyl halide, benzyl ether, aromatic or aryl ether, or optionally substituted versions thereof, and R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are not significantly affected by the reaction. In certain embodiments, the diarylalkylphosphonate may be diphenylmethylphosphonate.

Optionally substituted triarylphosphite may have the general formula (III):

where R _1a , R _1b and R _1c may be individually an aromatic or aryl group, or a substituted aryl group of formula (II), and in some embodiments, the triarylphosphite may be triphenylphosphite.

Optional substituted trialkylphosphites may have the general formula (IV):

where R _2a, R _2b and R _2c may be individually C ₁ -C ₂₀ alkyl, and in some embodiments, the trialkyl phosphite may be trimethyl phosphite.

Optionally substituted alkanols in the embodiments described herein may have the general formula (V):

where R ₈ and R ₉ may independently represent hydrogen or C ₁ -C ₂₀ alkyl, and in some embodiments, the optionally substituted alkanol may be methanol.

In embodiments of the invention, various molar ratios of the reactants may be used. In some embodiments, the optionally substituted trialkylphosphite or the optionally substituted alkanol may be present in a molar excess with respect to the optionally substituted triarylphosphite, which is at least less than about 10%. In other embodiments, the optionally substituted trialkylphosphite or optionally substituted alkanol may be in a molar excess of at least about 9.5%, 9.0%, or 8.0% with respect to the optionally substituted triarylphosphite, and in other embodiments of the implementation of the optionally substituted trialkylphosphite or optionally substituted alkanol may be in a molar excess of from about 0.0% to about 10% molar excess with respect to the optionally substituted triarylphosphite, or from from 0.01% to about 3.0% molar excess with respect to the optionally substituted triarylphosphite. In certain embodiments, the optionally substituted trialkylphosphite or the optionally substituted alkanol may be present in a molar excess of less than 1% with respect to the optionally substituted triarylphosphite. Without being bound by any theory, when an optionally substituted trialkylphosphite or an optionally substituted alkanol is present in a range of from 0.0% to about 3.0% with respect to an optionally substituted triarylphosphite, formation of by-products such as, for example, dimethylphenylphosphite can be avoided.

In embodiments in which the optionally substituted alkanol or optionally substituted trialkylphosphite is present in a molar excess with respect to the optionally substituted triarylphosphite, the resulting diarylalkylphosphonate may be substantially free of contaminants such as, for example, residual triarylphosphite, residual trialkylphosphite, or a combination thereof. Residual triarylphosphite can be difficult to separate from diarylalkylphosphonate, since the boiling points of the two components are close and triarylphosphite may not be distilled off from diarylalkylphosphonate. In addition, even a small amount, for example, less than 1% of the total product, residual triarylphosphite can interact with conjugated bisphenols and can be reduced to the form of toxic phosphines. Additionally, oxidized bisphenol can form colored by-products. In any case, the resulting oligo- or polyphosphonate may be spoiled and unsuitable for use, or extensive distillation may be required to remove by-products or residual reagents from the diarylalkylphosphonate product, which significantly increases the time and cost required to obtain a usable product.

In some embodiments, a catalyst may include, but is not limited to, alkyl chlorides, alkyl bromides, and alkyl iodides in which the alkyl groups may carry one or more of a variety of substituents. In other embodiments, the implementation of the catalyst may be methyl iodide. Other known alkylating catalysts that can be used in the present invention include, but are not limited to, sulfonic acid esters, sulfuric acid esters and sultones. Strong acids, such as, but not limited to, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, and perfluorooctanesulfonic acid, can also serve as catalysts in this reaction. The amount of catalyst added to the reaction mass may vary in different embodiments. However, in some embodiments, the catalyst may be present in an excess of about 0.01% to about 10% by weight relative to the total weight of optionally substituted triarylphosphite and optionally substituted trialkylphosphite or optionally substituted alkanol. In specific embodiments, the implementation of the catalyst may be less than about 0.15 wt.% Relative to the total mass of optionally substituted triarylphosphite and optionally substituted trialkylphosphite or optionally substituted alkanol. Without being bound by any theory, when the catalyst is less than about 0.15% by weight of the total reactants, the formation of by-products such as, for example, iodobenzene and triphenyl phosphate can be avoided.

Although the optionally substituted trialkylphosphite or the optionally substituted alkanol and the catalyst may be individually presented in the above range, in certain embodiments, the optionally substituted trialkylphosphite or the optionally substituted alkanol and catalyst may both be present in the range described above. For example, in one embodiment, the optionally substituted trialkylphosphite or optionally substituted alkanol may be in a molar excess of less than 10% by weight of optionally substituted triarylphosphite, and the catalyst may comprise less than 0.15% by weight relative to the total weight of optionally substituted triarylphosphite and optionally substituted trialkylphosphite or optionally substituted alkanol. In another embodiment, the optionally substituted trialkyl phosphite or optionally substituted alkanol may be in a molar excess of from about 0.01% to about 3% by weight relative to the optionally substituted triaryl phosphite or less than 1% by weight relative to the optionally substituted triaryl phosphite, and the catalyst may be less than 0.15% by weight relative to the total weight of optionally substituted triarylphosphite and optionally substituted trialkylphosphite or optionally substituted alkanol.

The method of the present invention is not limited to how the catalyst is added. For example, the catalyst may be combined with optionally substituted triarylphosphite before adding optionally substituted alkanol or optionally substituted alkylphosphite, or the catalyst may be added simultaneously with the addition of optionally substituted alkanol or optionally substituted alkylphosphite.

In embodiments, one or more reagents and / or catalysts may be added on top of the upper surface of the reaction mixture. For example, an optionally substituted trialkylphosphite or an optionally substituted alkanol and catalyst may be added to the reaction mixture containing an optionally substituted triarylphosphite or triarylphosphite and a catalyst through a dropping funnel. The alkanol or mixture of alkanol and catalyst can then be fed in small portions to the surface of the reaction mixture in a controlled manner. In other embodiments, an optionally substituted alkanol or an optionally substituted alkanol and catalyst may be pumped into the reaction mixture, thereby introducing an alkanol or mixture of alkanol and catalyst from below the surface of the reaction mixture. Injection of the components into the reaction mixture may allow a continuous stream of optionally substituted trialkylphosphite or optionally substituted alkanol and catalyst to be fed into the heated optionally substituted triarylphosphite. Or, optionally substituted alkanol can be fed into the heated triarylphosphite catalyst mixture from below the surface of the reaction mixture in a controlled manner. Without being bound by any theory, the addition of components, such as optionally substituted alkanol, optionally substituted trialkylphosphite and / or catalyst, below the surface of the reaction mixture may make it possible to determine the residence time of this component in the reaction mixture, increasing the time during which the reactants can react since the heat generated during the reaction or the desired reaction temperature can be such that one or more of these components evaporate from the reaction mixture if add them to the surface of the reaction mixture. Adding the reaction components from below may result in increased reaction efficiency, conversion time and product yield. In other embodiments, the feed rate of the optionally substituted trialkylphosphite or the optionally substituted alkanol and catalyst can be increased by pumping these components beneath the surface of the reaction mixture, reducing the reaction time compared to the method of adding from above by at least half.

Without being bound by any theory, in embodiments where the triarylphosphite reacts with trialkylphosphite, the synthesis of diarylalkylphosphonate can occur, for example, as shown in Scheme (I):

where R ₁ may be an aromatic or aryl group, or a substituted aryl group of the formula (II), and R ₂ may be C ₁ -C ₂₀ alkyl.

In embodiments where the triarylphosphite is reacted with an optionally substituted alkanol, synthesis of diarylalkylphosphonate can occur, for example, as shown in Scheme (II):

where R ₁ may be an aromatic or aryl group, or a substituted aryl group of the formula (II), and R ₂ may be C ₁ -C ₂₀ alkyl.

In still other embodiments, the triarylphosphite catalyst mixture may be formed by combining an optionally substituted triarylphosphite with a catalyst, such as, for example, a methyl halide catalyst, and heated to a predetermined reaction temperature before adding the optionally substituted trialkylphosphite or optionally substituted alkanol, resulting in a catalyst of the general formula ( VI):

where R _1a , R _1b and R _1c may be an aromatic or aryl group, or a substituted aryl group of the formula (II); R ₁₀ may be hydrogen or C ₁ -C ₂₀ alkyl; and X may be a halide such as F, Cl, Br or I. The catalyst in such embodiments may be stable at ambient temperature or may be heated to a temperature of up to about 260 ° C. without loss of catalytic activity. The stability of the catalytic complex may be such that the catalytic complex can be stored for an indefinite period of time. The reaction by which the catalyst is formed in these embodiments may be reversible at high temperature. For this reason, in some embodiments, the catalyst of general formula VI and optionally substituted triarylphosphite can be heated to a predetermined reaction temperature of at least about 210 ° C., and optionally substituted alkanol or optionally substituted trialkylphosphite can be added to form the reaction mixture used to obtain an optionally substituted diarylalkylphosphonate. In such embodiments, the implementation of diarylalkylphosphonate can be obtained without the use of an additional catalyst.

Advantageously, the diarylalkylphosphonates obtained by the embodiments of the invention can be obtained in one reactor, since it may not require isolation or purification of the intermediates. Additionally, by-products such as dialkyl aryl phosphite, triaryl phosphite, arylols, methoxyaryl, diarylalkyl phosphates, diaryl methyl phosphite and residual triaryl phosphite can be minimized or eliminated, so that one or more separation steps at which the by-products are removed may not be necessary. In certain embodiments, the formation of triaryl phosphate as a by-product can be avoided. The diarylalkylphosphonates obtained by the present invention can therefore be easily purified or obtained with a purity level sufficient for subsequent reactions.

A wide variety of diaromatic alkyl phosphonates can be prepared using the present invention. They can be used as monomers for the synthesis of polymers, such as, but not limited to, polyphosphonates and copolymers of carbonates and phosphonates. These polymers have exceptional fire resistance and are used in a wide range of applications found in everyday life.

Given the broad outline of the invention, a more complete understanding can be obtained by referring to the following examples, which are presented for illustrative purposes only and do not limit the invention.

EXAMPLE 1

Excess 7.0% trimethylphosphite and 1.0 wt.% Iodomethane

A 5-liter flask equipped with a lowering mixer, an oil bath, a dropping funnel, a water cooling condenser with a nitrogen bypass and a thermometer was used as a reactor. 2560 g (8.0 mol) of triphenylphosphite and 36.8 g (0.256 mol, 1 wt% of the total reagents) of iodomethane were charged into the flask, and these components were stirred at room temperature. This mixture was then heated in an atmosphere of N ₂ to a reaction temperature of 240 ° C. During heating, neither an exothermic effect nor boiling with return of liquid from the condenser was observed. During heating, some discoloration occurred, but it disappeared after the addition of trimethylphosphite. After the reaction temperature was reached, a solution of 550 g (4.3 mol, 7.0% molar excess) of trimethylphosphite was added from a dropping funnel over 3 hours. After addition, the reaction temperature was maintained at 240 ° C. for one more hour. Then the product was cooled and analyzed.

The crude product was analyzed by gas chromatography. Pure standards for each starting material and product were used to establish retention times. This analysis determined the amount of the desired product, residual starting materials and any by-products. The crude reaction mixture was diluted with acetone and introduced into a gas chromatograph. All measured peaks were attributed to chemical structures. Analysis of the mixture by gas chromatography gave the following results:

Dimethylphenylphosphite (DMPP (i)) = 3.25% Diphenylmethylphosphonate (DPP) = 94.70% Triphenylphosphate (TPP (a)) = 2.05% Phenol = 0,0% Iodobenzene = 0,0%

EXAMPLES 2-4

Excess 0.80% trimethylphosphite and 0.15 wt.% Iodomethane

In each of Examples 2-4, a 12 L flask equipped with a dip mixer, an oil bath, a dropping funnel, a water cooling condenser with a nitrogen bypass and a thermometer was used as a reactor. 6773 g (21.17 mol) of triphenylphosphite and 12 g (0.084 mol, 0.15 wt% of the total reagents) of iodomethane were charged into the flask and these components were stirred at room temperature. This mixture was then heated in an atmosphere of N ₂ to a reaction temperature of 240 ° C. During heating, neither an exothermic effect nor boiling with return of liquid from the condenser was observed. During heating, some discoloration occurred, but it disappeared after the addition of trimethylphosphite. After the reaction temperature was reached, a solution of 1365 g (10.67 mol, 0.80% molar excess) of trimethylphosphite was added from a dropping funnel over 3-3.5 hours. During the feed of trimethylphosphite, boiling was not observed with the return of liquid from the condenser. After addition, the reaction temperature was maintained from 240 ° C. to 260 ° C., accompanying the reaction. The reaction was stopped after gas chromatography of the reaction mixture showed that traces of the starting materials could not be detected. The results of the analysis of the mixture by gas chromatography are shown in Table 1. Table 1 shows the product (diphenylmethylphosphonate (DPP)) and reaction by-products (triphenylphosphate (TPP (a), phenol and iodobenzene).

Example No. DPP,% TPP (a),% Phenol,% Iodobenzene,% 2 99,4 0.6 0,0 0,0 3 99.1 0.9 0,0 0,0 four 98.7 0,0 1.3 0,0

EXAMPLES 5-7

Excess 1.17% trimethylphosphite and 0.10 wt.% Iodomethane

In each of Examples 5-7, a 12 L flask equipped with a dip mixer, an oil bath, a dropping funnel, a water-cooled condenser with a nitrogen bypass and a thermometer was used as a reactor. 6773 g (21.17 mol) of triphenylphosphite and 8.0 g (0.056 mol, 0.10 wt% of the total reagents) of iodomethane were charged into the flask, and these components were stirred at room temperature. This mixture was then heated in an atmosphere of N ₂ to a reaction temperature of 240 ° C. During heating, neither an exothermic effect nor boiling with return of liquid from the condenser was observed. During heating, some discoloration occurred, but it disappeared after the addition of trimethylphosphite. After the reaction temperature was reached, a solution of 1370 g (10.71 mol, 1.17% molar excess) of trimethylphosphite was added from a dropping funnel over 3-3.5 hours. During the feed of trimethylphosphite, boiling was not observed with the return of liquid from the condenser. After addition, the reaction temperature was maintained from 240 ° C. to 260 ° C., accompanying the reaction. The reaction was stopped after gas chromatography of the reaction mixture showed that traces of the starting materials could not be detected. The results of the analysis of the mixture by gas chromatography are shown in table 2. Table 2 shows the product (diphenylmethylphosphonate (DPP)) and reaction by-products (triphenylphosphate (TPP (a), phenol and iodobenzene).

Example No. DPP,% TPP (a),% Phenol,% Iodobenzene,% 5 99.5 0,0 0.5 0,0 6 99.5 0,0 0.5 0,0 7 98.4 0,0 1,6 0,0

EXAMPLES 8-10

Excess 1.25% trimethylphosphite and 0.074 wt.% Iodomethane

In each of Examples 8-10, a 12 L flask equipped with a dip mixer, an oil bath, a dropping funnel, a water cooling condenser with a nitrogen bypass and a thermometer was used as a reactor. 6773 g (21.17 mol) of triphenylphosphite and 6.0 g (0.042 mol, 0.074 wt% of the total reagents) of iodomethane were charged into the flask, and these components were stirred at room temperature. This mixture was then heated in an atmosphere of N ₂ to a reaction temperature of 240 ° C. During heating, neither an exothermic effect nor boiling with return of liquid from the condenser was observed. During heating, some discoloration occurred, but it disappeared after the addition of trimethylphosphite. After reaching the reaction temperature, a solution of 1372 g (10.72 mol, 1.25% molar excess) of trimethylphosphite was added from a dropping funnel over 3-3.5 hours. During the feed of trimethylphosphite, boiling was not observed with the return of liquid from the condenser. After addition, the reaction temperature was maintained from 240 ° C. to 260 ° C., accompanying the reaction. The reaction was stopped after gas chromatography of the reaction mixture showed that traces of the starting materials could not be detected. The results of the analysis of the mixture by gas chromatography are shown in table 3. Table 3 shows the product (diphenylmethylphosphonate (DPP)) and reaction by-products (triphenylphosphate (TPP (a), phenol and iodobenzene).

Example No. DPP,% TPP (a),% Phenol,% Iodobenzene,% 8 99.3 0,0 0.7 0,0 9 one hundred 0,0 0,0 0,0 10 99,4 0,0 0.6 0,0

EXAMPLE 11

Excess 0.80% trimethylphosphite and 0.074 wt.% Iodomethane

A 12-liter flask equipped with a lowering mixer, an oil bath, a dropping funnel, a water cooling condenser with a nitrogen bypass and a thermometer was used as a reactor. 6773 g (21.17 mol) of triphenylphosphite and 6.0 g (0.042 mol, 0.074 wt% of the total reagents) of iodomethane were charged into the flask, and these components were stirred at room temperature. This mixture was then heated in an atmosphere of N ₂ to a reaction temperature of 240 ° C. During heating, neither an exothermic effect nor boiling with return of liquid from the condenser was observed. During heating, some discoloration occurred, but it disappeared after the addition of trimethylphosphite. After the reaction temperature was reached, a solution of 1365 g (10.67 mol, 0.80% molar excess) of trimethylphosphite was added from a dropping funnel over 3-3.5 hours. During the feed of trimethylphosphite, boiling was not observed with the return of liquid from the condenser. After addition, the reaction temperature was maintained from 240 ° C. to 260 ° C., accompanying the reaction. The reaction was stopped after gas chromatography of the reaction mixture showed that traces of the starting materials could not be detected. The results of the analysis of the mixture by gas chromatography are as follows:

Diphenylmethylphosphonate (DPP) = 98.65% Triphenylphosphate (TPP (a)) = 0,0% Phenol = 1.35% Iodobenzene = 0,0%

Claims (20)

1. The method of producing diarylalkylphosphonate, including:
combining at least one triarylphosphite and at least one catalyst to form a triarylphosphite catalyst mixture;
heating the triarylphosphite catalyst mixture to a reaction temperature that is from about 210 ° C to about 260 ° C,
addition to a heated triarylphosphite catalyst mixture
(i) at least one trialkylphosphite in a molar excess of 0.01% to about 3% based on triarylphosphite; or
(ii) at least one alkanol in a molar excess of from 0.01% to about 3% based on triaryl phosphite; and the interaction of a triarylphosphite mixture and at least one trialkylphosphite or at least one alkanol with the formation of diarylalkylphosphonate. 2. The method according to claim 1, in which the trialkylphosphite is present in a molar excess of less than about 1% of triarylphosphite. 3. The method according to claim 1, in which the triarylphosphite has the General formula

where R _1a , R _1b and R _1c , each independently, have the General formula (II):

where R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are each independently selected from hydrogen, trifluoromethyl, nitro, cyano, C ₁ -C ₂₀ alkyl, aromatic radical, halide, C ₁ -C ₂₀ alkyl ether, benzyl halide, benzyl ether, aromatic ether and combinations thereof. 4. The method according to claim 1, in which the triarylphosphite is triphenylphosphite. 5. The method according to claim 1, in which the trialkylphosphite has the General formula (IV):

where R _2a , R _2b and R _2c each independently represent C ₁ -C ₂₀ alkyl. 6. The method according to claim 1, in which the trialkylphosphite is trimethylphosphite. 7. The method according to claim 1, in which the alkanol is selected from alkanols of General formula (V):

where R ₈ and R ₉ each independently are hydrogen or C ₁ -C ₂₀ alkyl. 8. The method according to claim 1, in which the alkanol is methanol. 9. The method according to claim 1, in which the trialkylphosphite or alkanol is added to the heated catalyst mixture by a method selected from:
adding trialkylphosphite or alkanol under the surface of the heated triarylphosphite catalyst mixture; adding trialkylphosphite or alkanol to the surface of the heated triarylphosphite catalyst mixture; and their combinations. 10. The method according to claim 1, in which the catalyst is an alkylation catalyst. 11. The method according to claim 1, in which the catalyst is an alkyl halide of General formula (VII):

where R ₁₀ represents C ₁ -C ₂₀ alkyl, and X represents a halide. 12. The method according to claim 1, in which the catalyst is CH ₃ I. 13. The method according to claim 1, in which the catalyst is in excess of less than about 0.15 wt.% Of the total weight of trialkylphosphite or alkanol and triarylphosphite. 14. The method according to claim 1, in which the reaction temperature may be at least higher than the exotherm that occurs when triarylphosphite is mixed at room temperature with a catalyst and trialkylphosphite and heated. 15. The method according to claim 1, further comprising maintaining the reaction temperature during the addition of the mixture. 16. The method according to claim 1, in which the obtained diarylalkylphosphonate mainly does not contain triarylphosphite. 17. The method according to claim 1, in which the obtained diarylalkylphosphonate mainly does not contain an aryl halide. 18. The method according to claim 1, further comprising using the obtained diarylalkylphosphonate in subsequent reactions without purification of the diarylalkylphosphonate. 19. The method according to claim 1, in which the triarylphosphite catalyst mixture is stored for an indefinite period of time before heating. 20. The method according to claim 1, in which the interaction step includes heating to a reaction temperature at least above the exotherm that occurs when the triarylphosphite is mixed at room temperature with a catalyst and trialkylphosphite.